Electric-circuit control



Dec. 23, 1930. C l. c. HANSON 1,785,773

ELECTRIC CIRCUIT CONTROL Filed April 15, 19,26

[NVENYOR J44 a #mm, By 7710M, M

A ORNEYS Patented Dec. 23, 1930 Urrs IRA C. HANSON, OF RACIN E, WISCONSIN ELECTRIC-CIRCUIT CONTROL Application filed April 15,

This invention relates to improvements in electric circuit controls, and more particularly to a temperature control for electric circuits.

It is one of the. objects of the present invention to provide an electric circuit control for incubators, electric signs, and like devices, said circuit having thermally controlled means for making and breaking the circuit.

A further object of the invention is to provide an electric circuit temperature control provided with regulating means whereby the circuit can be automatically opened and closed at predetermined temperatures.

1 A further object of the invention is to pro vide a control of the class described having an adjustable means permitting any predetermined range of degrees prior to the action of the circuit control.

0 A further object of the invention is to provide a device of the class described for main taining a constant temperature Within a chamber or compartment.

A further object of the invention is to provide a temperature control for electric circuits which is of very simple construction, is inexpensive to manufacture and install, is simple and efiicient in operation, is strong and durable, and is weil adapted for the purposes described.

With the above and other objects in view the invention consists of the improved tent perature control for electric circuits, and its parts and combinations as set forth in the claim, and all equivalents thereof.

In the accompanying drawing in which the same reference characters indicate the same parts in all of the views:

Fig. 1 is a side view of the improved temperature circuit control shown in connection with a heated chamber;

Fig. 2 is a sectional view taken on line 2-2 of Fig. 1;

Fig. 3 is a plan view of the control and cover of the chamber; and

Fig. 4 is a perspective detail view of the pivotal contact member.

Referring now more particularly to the drawing it will appear that the numeral 8 designates a closed compartment or chamber 1926. Serial No. 102,236.

such as an incubator or an electric sign and the numeral 9 designates the cover or top thereof. Depending from the inner surface of the top 9 is a tubular bracket 10 terminatingin a U-shaped arm 10, at right angles 55 to the bracket proper. Carried by the arm 10 is a sealed disc 11 which is hollow and filled with a temperature responsive fluid as ether or the like. Said disc is formed with. a hub portion 12 having a depression in which is seated the lower end portion of a rod 13 which extends through the tubular bracket 10 and the top 9 and terminates exteriorly of the same.

The upper end portion of the rod has fixed thereto a circular plate is positioned between the bifurcated end portion of a pivotal lever 15 which is mounted on the side of an insulated block 16 secured to the outer surface of the member 9, as shown in Figs. 1 and 3. The end of the pivotal lever 15, opposite the bifurcated end, carries a right angularly eX- tending metallic contact strip 17 adapted for movement within a slot 18 provided therefor in the insulated block 16 and for engagement with a struck-up metallic contact member 19 secured to the block 16 and extending over the slot 18 and strip 17 Circuit wires 20 and 21 terminate at the contact members 17 and 19 so that when said contact members are in engagement the electrical circuit will be completed. Included in the electric circuit and within the compartment 8 are one or more incandescent bulbs 22 or other heating units.

The arrangement of the device is such that the circuit is normally closed and when the interior of the compartment becomes heated to a predetermined temperature the expansion of the fluid within the disc 11 will cause a corresponding expansion of the walis of the disc thereby raising the rod 13. This movement of the rod will cause the circular plate 1a to engage an adjustable screw 23 depending from the upper bifurcated portion of the lever 15 to pivot said lever and separate the contact members 17 and 19, breaking the electrical circuit. When the temperature within the compartment has lowered to a predetermined temperature the contraction of the disc 11 will have lowered the plate 14 suiticiently to engage a lower screw 24, whereby the lever 15 is pivoted back to normal position, engaging the contact members and again completing the circuit. The adjustable screws 23 and 24 permit the device to be adjusted for a desired range of degrees before the circuit is completed or broken.

From the foregoing description it will be seen that the improved temperature circuit control is of very simple and novel construction, and is well adapted for the purposes set forth.

What I claim as my invention is: A thermostatic circuit controller, comprising a support of insulating material, a fixed contact member carried thereby, a lever pivotally mounted on said support and having a bifurcated outer end portion, adjustable screws extending through said bifurcated portion, a contact member carried by the inner end portion of said lever and engageable with said fixed contact member, a tubular bracket, a thermostatic disc carried by said bracket, a rod movably mounted within said bracket and projecting from the ends thereof, one end portion of said rod being supported by said thermostatic disc to be moved thereby, and a plate fixed to the outer end of said rod and arranged for restricted movement between the adjustable screws in the bifurcated portion of said lever to move the lever in both directions upon contact with the screws. In testimony whereof, I aflix my signature.

IRA C. HANSON. 

